Bioaffinity Screening with a Rapid and Sample-Efficient Autosampler for Native Electrospray Ionization Mass Spectrometry

Fast and efficient handling of ligands biological targets are required in bioaffinity screening based on native electrospray ionization mass spectrometry (ESI-MS). We use a prototype microfluidic autosampler, called the “gap sampler”, to sequentially mix individual small molecule together with target protein compare results data from thermal shift assay surface plasmon resonance. In first round, all three techniques were used for 110 against bovine carbonic anhydrase II, which resulted five mutual hits some false positives ESI-MS presumably due high ligand concentration or interferences dimethyl sulfoxide. second 33 compounds screened lower concentrations less complex matrix, resulting only true ESI-MS. Within cycle time 30 s, dissociation constants determined within an order magnitude accuracy consuming 5 pmol than 15 per compound. third accurately titration experiment. Thus, gap sampler can rapidly efficiently be high-throughput screening.